Machine for generating and cutting irregular gears.



. E. 11. Fmovvs.

MACHINE VFOR GENERATING AND CUTTlNG IRRE GULAR GEARS.

APPLICATION FILED MAH. H, 1914.

.4 SHEETS-511mm.

1111.! IIIH1| 1411\ I wh mm, 1.41-1.- .1 1 1, t j 11 1111111 111 N NN( bmif Mar.'

4 SHEETS--SHEU 3.

l ,Patented EUR. FELLOWS. MACHINE FOR GENERATING AND CUTTING IRREGULAH GEARS'.

APPLICATION FUED MAR. 1i, 1914.

1 nmlnnmulm Mmmm l Il E. R. FELLGWS.4 Mama FOR GENERAHNGAND cume IRREGULAR Gil/ms.

APPLlCATON AFILED MAR. l'l 15H4. v Patented Maur. 28, 1916.

Y A AV if Animation-Iniciante@i el county fof `lllindeor i: have lnyented `eertam vinti"` g Irregular Gears, `infgiis'a specitication.` l inventionlrelatesz to v a` maehinej for gearel on ftheprinciple `explained patentsffgranted vto yme March "B0, June -1121901111N0' y otter-Shaped like a gear ngf` gp riplleralffprojections similar t gear `teeth isfearried pastlthe edge 912 No. 1,028,343; m

ol eut' the yteeth in the an the-baal;

h netetl `"f 'the Same sPCh, V heprojectioneoftheeut- .he niaehines `described f in Said pat- `tithe lmetlliodfaeoording-to which such are Worlxze; hreeult linproducing rm `hay( g equally `spaced teeth [all .p f likeianc allteqnally distant y from ",jrandj`1th oth yo'f which` isa `gear .s .lineof teeth eeentric sto` the cen gear in `Varioli's lforrnsf and: degrees. Snell` irregular Vgears. have f two {ofsuclifa `geared couple, one members ,frcnerally the` pinioniis` re` lane/lout Withrespectfto erfineniberi `Such an ir irsegtan; nctbe Iproduced 1d; machines heretofore em-` litter and `the .Work Vare free@` .l i y y bythe present" inven- States, and resident vrovernentslfin Machines i mi et .the Sam `fune generate albe" of lsneli teethlvtofrnesh properly with is a plan View of the machine with the 1 pro'vement associated therewith. Fig. i ie rwpair, onelofewhich is a `pinlon` of` obesa` which., are` sy-rntrnetriallyh ari simillarytoyone another,I In

Brionk imornnvron ennnngaaimennn letterine mencionan anims'.

n 1,914. seria; Nogzaoes.

` ftion ha'sfbeen to provide Ineens adapted for use n n .Connfection Vwith afgear generating-` machine operating on the general principlee "deseribedvin the patents y aboveeited, by

and f th blank bein' out may be alter d t during progress-.o vthe generating a d which the/relativepositions of the cutterl .ilrnnnowsgffon",srnnerrnmi, "ynnnronmfnssenoa no THE FELnows GEAR i rnngcoiaramfqn srnmerlmm, ynnmonfr, A ComonA'rIoN or VERMONT.

t entting o eration, in amanner similar toy' V that in Jlhieh the pinion and the irregular' gear` of the, geared couple are shifted rela ftiyely to one another dnringtheoperation of siichlgea-red couple; and also to electyaria'- I tions in the rate of rotating the cutter to qonapensate for "`the Variation in "fdistance of dilferentteeth f the irregulargear from the axis of thegear, so thatthe teeth"`gen teetltof. the cutter.

trated the embodiment 1 of my. invention y in meains'adapted to be applied to whatl term mylstandard machine, that is, `a machine of which "the priniplesand many of the de- Ytails of forni and construction are'illustrated c in my Patents 676,277 and 1,028,343 1before mentioned, `altl'lough without intendingtto chine i.

applied thereto, as isy necessary to enable the` .,ypresent invention to be understood. Figui?,

a front elevation on a larger'scalept' parts shown in Fig. l, showing sonieo theY parte in Section; Fig. 4 1s a plan ylew of the mechanism in which my presentinven` tien is embodied, on a .scale larger than Fig; 2; Fig. 5 is :mend ifiew as seen En'rm theyleft of Fig'. el of this mechanism. is' a horizontal sectional View of the for varving the rate of indexing the ein Fig. '7 is' a horizontal sectional View-on .sine 1T-7` ofFig. 3. Fia. 8 is a Vertical sectional View en line 8--8 oi'` Fig. 3. Fig. 9 isa plan` vievveot` the blank of the irregular `near which the particular mechanism herein illus'-4 .trated is designed to out. the cutter being shown in operative relation to such blank. i. Thesame reference characters indicate the Same parts in all the figure 7 imit the invention to that partfonlarf ma In `the accompanying draWings,Figure l` re ferated may be spaced on the fpitch"v line" equally to the spaeing of the projections or Ing' the present application I` have" illnsl` l y' Referring first t'o Figs. 1 ani-12,110 sents the pedestal of the machine,

sents the gear blank which-is secured to a. table 12 carried 'bya spindle 13, and'14 rep- I resents the cutter. "Such cutter is formed with roj'ectionsl correspondingin shapetoj ,the teeth ofa gear,- andtheir lower edges are formed as cuttingedges, wherebysaid cutter may-act asia planing vtool to 'remove Vthe ma- .terialiof the gear blank' when carriedy acrossv that portion of 'the blank in which the teeth are to be lformed. On-.account of the simi? 4 larity in outline of theproje'etion's ofthev cutter 'to gear teeth, sueh projections are usually termed lteeth in the art, and'will be s'o terinedgin this description.

-The gear blank which is shown in plan l .view in detail in Fig. 9 is designed to be' inad-e into aninternal gear .of irregular -form yhaving' four lobes of equal lsize andy symmetrically arranged. TheV blank therefore has an internalvange 15` of sufficient depth. to 'provide teeth `,when properly cut' away, and this flange has'y the gie/neral outline'of the line on which theteeth when out are arranged. The forni and arrangement of the lobes can be clearly determinedfrom` Fig 9.' That-portion of the lip 15 extend" "ing between the points A and B constitutes one ofthe lobes, occupying ninety degrees of the angular spacevabout the'centel C of the blank. Evidently the points in each half of each lobe are uncqually distant fromv f the c enterof the gearblank, and in consequence the only'way in 'which a cutter of regular form may be made to'generatethe.

teeth of the gear, when thegeneratin'g inovements of the cutter and gear take place 'about their own respectivel axes, is toproduce a relative movementbetween the axes of the cutter and gear blank during the course of cutting teeth on` each lobe of 'the blank.` A p art of my'present object' has y been to provide a means for producingsuch a change in the relation of these axes, andy in the present embodiment of my invention Ihave provided a means for moving'the cuttcrto secure this relation.'A

Thecu'tter 1s mounted upon the lower en of an upright shaft 16 mounted with provi-l sion for endwise movement and also rotation 1n a saddle or` slide 1.7 winch 1s 'supported on a horizontal guidewary 18 inthe duce the planing cuts are given by a manncrillustrated in my prior patents referr-ed to, The reciprocating endwiseinovements of the cutter shaft necessary to pro- 19' (Fig'S), meshingwith a rack 20 which is engaged with the cutter shaft 16. Said` -pinion is secured to a shaft 21 which isgoseil?r lated by a transverselymovingrack d' by a crank and meshing with a second ion on the shaft, as fully illustrated and plained in my Patents 676,227 a'nd1,028A 43. Rotary vmovements are given to the icutpinion ter "Icone Y, 22 which i drives a 'pulley' 23,V the latter pulley-being mounted' on a' shaft 24'jand driving' the 'same through a differential gearing, 25, 26 and 27; shaft 24 ldriving'a worm 28 which meshes` with a worm wheel Qt-properly coni. -nested with the cutter shaft 16, and said 4shaft 24 also driving 'af beveled gear 30 mesh- `ingwith a ybeveled gear 31 on'a shaft 32;

said -shaft32 driving the work spindle 13 through change gears anda worm and wheel mechanism, all ras clearly shown in myPatents 676,227 'and1,'028,343,to which lreference 'is directed for a complete description. The`shaft'24carries a pinion 33 meshing with a gear 34,011 a countershaft k35 in rear of shaft 24. Said countershaft also carries awor'm 36 in mesh with a worin wheel 37 on a transverse 'shaft 38. ySaid shaft 38 carries a cam 39 which osoillates'a lever 40, said lever being pivoted" at 41 on' a portion of the inachine'frame and having an arm 40 pivotally connected by a pin 42 with `a con- 4 necting rod v43. That portion of level` 40 whichengages the cam is provided with -two y anti-friction rolls 44 and 45 engaging the ofthe ca m 0n opposite sides of f periphery the axis thereof, so that the cam-positively moves the lever' vin both directions. .The connecting rod 43'is pivoted u'pona pin 46 which is connected with arod 47 being held in jaws 48 projecting fro'nja sleeve 49 which is mounted 'uponfsaid-rod fand issecured thereon bv a'nutv 50.,"y Thefrod 47 has a screw threaded portion L on which is mounted a nut 52 (see Fig.=7), su'chnut bei*l cutter. Nut '52 is provided a't one end with a bevel gear 54 which meshes vwith v,al bevel" gear 55 on a shaft 56 projecting through the ing rotatably supported 'in bearings 53 connected with the saddle 17 v `which "carries the front ofthe saddle and 'having a square end 57 to be engaged with'fa wrench 'or key.

The rod 47 is movable endwise in fixed bearings 58 and 59, and is also rotatable,

being permittedv to turn I'within the sleeve 49.

lsleeveis conlin'ed at one end between a. shoulder 60 of the rod and a/washer 61 in contact Jwith the nilt 50,'so that the movements -im-l p arted'to the' sleevef49 by'link 43 arte glso',v transmitted to the 4screw rod, without fire#VA venting rotation of the-latter at need. The outer end ofthe screw .rod passes throng-fh` a.

sleeveior hub 62 formingpart'ofthe gear 63, and is engaged with saidfsleeve by a' key 64 which is adapted t9 slidein a long keyway '65 of the-screw rod'.- Thus 4when `gear63 is rotated the, 'screw shaft 'is also rotated, but the screw may move freely end its i rotation.

vWise with respect to-'the'gear lregardless ofl The gear 63 is drivenin any suitablelmani Iner, as for instance, in the way the corre-l V` Asporuiling gears and nuts of my prior -patn ents b ereinhefore named are driven. to give.

rio Such epth feeduto thecntter. v The depth one which .I have chosen to employ in the complishedin essentially `thnesame present cese consists in making the worin 28, nylprioljpetens-referred'towith `Whihrotetes the cutter, movablefon the ptionwtfhehthe ISerienr' is `rotatedinf "shaft" 24; suitably moving the` worm so 52, :which is nnected givithfthe clit-V es tonugin'ent ordiininish the angular inove- 70 l"nsten-d1Loi'v being`- prevented inentsgven by it to the :Worm ,Wheel 29.

dfbeing niovelendwisebylgQThe'worIn; 28 is journeled in n bearing. 'f 1 connected ivitlithe saddle or cutter 'carriage esentimodeao` rnonnting-thescrew 17 endfisjsplined on the -shevtQlL' The Worm L t rinitsftheIcuttericarriagetobe moved wheel 29 is connected'withthe`- cutter spin- 75 byjr ation; ofshaft `56 `upto thetdlel inanydesiredmmanner, which I have encernentoftheoperetion, y'not'perticuliirly,illustrated since the `mode of to beV automatically fonne'ctionjiney be the saine es shown invmy" n henfpe'rinits fthe cu`tterpror pitentsfreferred to. lSecuredto the t thalccordingfto the@` Worm Wheel is e gear. 67,7Whi'ch meshes with 80 l *blankon which it e second "geer 68 which Vturnsupon a stud `69 f theblanlr; One/ff fixed inebracket 7 0. on theside of saddlev 17.*

` "moves'thelgcntter l Connectedwith gear 6.8` is e cern 71 which n th" jretlo ot'vtliepygeering bearsonan entifriction roll 72 carriedby a U "'24 drivesth'ecem lever `713,elso pivoted 4u pon e portion of the 85 suchrotetionftothel -cutter saddle. Such lever -73vhas alforked tiniereqniredriiorfthe"work Mend 74gA which 'Stritddles the Shaft '24 `and `roiighuthefengle:snbtended beersI onythe endof sleeve 75 which `is slid- "Inotherwordslthe eti-if ably mounted on said shaft endl enters one thetmtheretio'o ro Tend ofthebearingo. Sleevev s adapted 90 the rotation of `the to slide endwise end vis prevented from rotatto the retiogbetvveen ing by afkey which travels in as1ot 77 in berefteethylon" emchvilobeofthefgeer y theginner 4side of the bearing. n.anti fric nunibeirofjteethon thecntter. ,"lThe y tien thrust vbrewing 78 is interposed between of thefcain theeccentricities of the sleeve andthe end olworm 28. l Sleeve 95 lich outline;eresuch;` 75 is thus 'theabutment Whiehytekes the" es ofrnove thefcnttervcarriageesto mein'- thrustof vvorni 28, andperrnitse retrograde i ncebetivleenthe exisofthe cut-- "movement` 4of `the Worm ora'dvence's the tain iediste A y lipjothejgear blank lnfwhlch Worm according to the position of vthevcnm pindle; is i eq y t astowithdraw its support from the roll 72, invention releteslito` lthe abutment for the Worm is unsupported ragteuof generating roand thereforethe Worniirnperts to the Worm propcrtintoifthediS- )Wheel-en angular movement less than AprollleblnliOh WliiCllft; pol'tional to its own angular movementg 105 e erloffthe blanke` `'The `whereas if the Garnis-moved so; es to ediold cithereonuthe gear lolank l is vence the nbutxnenti', the wornifturns the tedf,is-lrotgited` iiniormljhffwherefore# Worm Wheel more than in proportiontoA its 'oinm the `delige jmlijvvhich are angular movement, actingztsfernck :tt that the centen Gere not" moved so` far time- As the shaft 24 is in constcnt .rote- 110 ,wvithxthelsa'me angular inoveinent,` tion, and the surface ofthe ceils smooth, `heqiointls in?thefjlangeinorefdistalnt the shifting beck and forth of the Worm is tl1e"center-l itislnecesserytlierefore to continuous and gradueh Therate of rotaucethe rate of generating rotfationof the `tion ofthe cern 7l is 4the saine that of thentteivhen the letternctsonfpertsofthe lip H'cam 39, being in the seine retioto the rotell "theeenter Gland to increase its'speed tion of the cutter as the ratio of the numro tin when "itlfncts ongpoints of the berof teeth on one lobe of the ,gear to the re temete fronij the center; als `other- `number of teeth onthe cutter," `l eteeth'cnt inthe blank-Would beun- "l beve not attempted describe vin `detail lnA .Qtlier, Wordsit iS of vthe operations ofthe mechneingenerating 120 tolcnttheteeth inthe blank andcntting the teeth of fr gear, as such op! suchteeth Will-beconjligntefto eigeei eratiogis', :ind the complete details of the 4in@itsfteethof the .saniesize pitch kmechanisms for carrying them ont are fully theiteethjof"tb.e`eutter,nnd@ofthe rete: of described in myl prior-patents already re- K "tingr t"ti`on``ofthe clitterinust' be ferred to. What I have described here is 12 d rniniehed properlyfto ineke .the nietms which l .have devised for enablingr he eethf` nfliichfareaciit in the gear ofunij f 'Iny standard machine to cut `irregular gears,

itch `eind? 'vvidthq There,` are `Several siich Ineens"` comprising devices for shifting `ltilvsiriation in therotetion the cutter toward and from the axis of the l, g" twbeiaccompliched. ffThe work,end`forvarying the speed of indexing 130 esernein elljpositions '4.71. Itis evident that if the cam issomoved 100 3 4rotation ofthe cutter, Vwhilethe work 'pril-i grosses. f 4

While" the illustrated embodiment `of 4inventionisan attachment vtomy standard". machine and is designed. to'fc'ut an intern'a l.

gear of four lobes, I desire'to say thatl have not intended this illustration to be a liz`nita tion of the inventionl." E Xelnial @reas- Well as internal gears may be cut and'l soalso may 'gears of more'or fewer lobes and halvsj., `ing greater or' 'les'sll eccentricit Y than1 the.` lobes oflthe gearhere illustrate 3 by merely substituting other cams for the cams" 39.`and.

7l, such other cams being designed. for the' lng.. claims any Lparticular work in hand. Idesire tostat'e also that I have not intended the illustraf tion'wand description here supplied. to be taken as limiting the invention to use in connection with my standard machine. Broadly considered the principles of thepresent invention are usable withany machine in which gear teeth are generated and k'cut by the action of a cutter bet-Weenwhich and the work there isa movement in vone direction to cut the teeth and in another direction.to

generate the tooth curves, or for indexing toJ cut l a succession of teeth. Consequently- 1t will be seen that I do not necessarilylimit 'the invention to a machine in which the out*y ter -headrather than the work spindle is shifted in accordance'with the irregularities of the work, nor to one in which the variation inthe rate 'of generating rotation .is-l 'applied exclusivelyA to the cutter.' For the urposes o'fthis invention and of the followar is considered irregular if the line in which its teeth are arranged is. not equidistant .at allA points" from the axis .about which the' gear, or a complementaigear in mesh with it, is designed to be rotated, regardless of whether or not the line. if teeth is geometrically regular or symmetrical with respect to any diameter of the gear.

or projection oi" which is designed and. adapted to cut a'groove or notch in thev tooth-bearing portion ofthe gear blank;

and-the relative motions otrotation Aand translation between the work and cutter,

transversely to the direction of.. 'cutting' movement serve at the same time to index" the work. and )to generate the v`tooth curves so that the teethfar'ecut on .thexdesired what 1 animandfieeireiejseeuefty. LeitersPatentisa'- ,1. Afma'chinefoi` cuttingiirregular gears comprising means for supporting a gear blank, a cutter, means for producing relative movements between the cutter and the blank supportlng Ameans to cut tooth 'grooves 1n a blank supported thereby, and means Jfor shifting oneof said elements in such direc- *tieneA` transverse to the direction of cutting The cutter is a formed cutter, each tooth blank at varying distances y:fro the blank. C

2.*A machine for cuttin vcomprising means' forfsu 'bla-nk, acutter havin toot yeral;projections' wit cutting yedges,*afr 'i rangedon a f curved pitCh'lnmandmeais for simultaneously rotating the eutt'e'rfant a'j i "7.5 j. about axes so arrangedas to causeA said cutv f regula-rline in21- blank supported by said'supportingmeans ter to" generate teeth inani the blank.-

comprising means foi; supportin blank, a cutter having tooth-shape -pei--i'phf-l eral proj cations-With cutting edges,arrang`edj v 3.v A machine for cutting irregular lgears'' ai geafrfv on. a curved pitch lin'e, and means for so.

rotating l theV cutter' and ,work hoflder'in. uni-- s 1 i, z'md at. the smetimefso shiftifn the axis of one of; them, as vtocaifise' the pito lineY of the cutter to roll tangentitanirregularpitch line" in the'wo'rk. 4. Amachine forcutti comprising `means for supporting a gear. blank, acutter having peripheral pro`ectionsv with ycutting edges'conforming to efut lines of gear'teeth arranged on `a curvedA pitch line, and means for rotating the cutter'.

and a blank supported byfsaid'supporting `means in unison with the samefspeed at the tangent point of their pitch lines about axes so variable as to the distance between them y'g irregular' gears, v

as to causesaid cutter to generate` teeth in I.

an1rregular line'in/ the blank. 5. A machme for cuttmg'irregular gears, comprising a cutter, a work holder ladapted to support a gear blank, means for produc ing repeated relative cutting movements 'between the cutter and the work holder across the' to oth-bearing lip of a blank supported by said -holder, and .means-for producing such further relative movements between the the tooth-bearing lip 'of a blank supported the work holder `in such directions transverse to the cutting movements as to-` cause *by said holder, and means for shifting one' of the elements constituted by the cutter and i2() the cutter tocut teeth in the work it suc I' cessive points 1n an irregular line.

7. A machine for cutting irregular 'geais," -comprising a cutting tool constructed to'cut notches in the tooth-bearing portion of -a gear blank, and meansfor producing such a combinatie if relative rotatory and: translative .ernents between said cutter5; andf i Bog 8, A "achine for cutting irregular gears, `=-eomprisi;'I ig"- a' gear blank holder," a rotatory ,cutter having projectionssimilar in.V outline.

and arrangement to'gearteethnneans for Y yproducing'such movementbetween the cut rter' and [the holder as tofj'cau'se-the projec- '10 vtions rof the vcuttertov make grooves 1n a- \blank carried bythe holder, AIfn'e'ans for rotatn means 'for rogressively lincreasing and die nnnishmgt e1 distancey between the axes of a :single ygear.l y i y ,9. A 'machine for-cutting irregular gears,

:j ter and thejholder as to cause Vthe projections ofthe cutter to make grooves in a lblankcarriedv by the holder, means for ro- [tatingfthefcutter and gear blank "in unison, ,`and`g1i 1`eans'for gradually altering thedis-4 @tance betwn the axes ,of the cutter and g vblankiby amounts, and in directions' accord'- :'ingto thedistances of'successiye.points in the irregular pitch line of the teeth being ,cutr from the axis of the blank. f

jlO. A machine vor cutting irregular 'vfgears, comprising `a gear blank holder, -a ro-H AYtatory cutterhaving projections similar in y Qutline'* and arrangement `to geary teeth, 7 means 'forproducing such movement be# Y tween" the cutter andthe holder as tocause the projections of thev cutter to make grooves a blank carried bythe holder, means 'for rotatingjthe cutter and gear blank in univson, and means for moving the. cutter progressively toward and away from thevaxis ofthe blank during the cutting operations. 11. A machine for generating and cutting thefteeth of irregular gears, comprising a r'gear blankholder and a gear-shaped plan# fing cutterarranged to rotate about approxi f'ffmatelyparallel axes, means for producing frelativemovement between said cutter and holder, in the general direction of such axes, means Vfor rotating saidy cutter and holderl simultaneously about their axes in the `r i'nanr'ier of interrneshing` gears,' and `means for -so shifting the cutter as yto in crease and diminish the distanceof its axis from lthatof 'the holder by amounts corresponding to diferences between the dis- "-,tances of.-dierent points in fan yirregular tooth-bearingportion of a gearfblank from the axis of theblanluv whereby tofgeause teeth to be cut' in an irregular linein such blank.y

12. A'f-gear generating. and butting machine including' in combination witha gear f sha-pcd `planing cutter, a work support,

means for producing relative cutting moveng the cutter and gear blank in unison, and:

the cutter and'blank in the course of cutting comprising agear blank holder, a' rotatory. vcutter' 'having projections similar' in outline and arrangement to gearteeth, means :for` producing ysuch movement between thecut ments between the c utterand work, and

means for 'varying therate of rotary movement of the support. v

-l3."A gear generatingan'd cutting ma chine including in combination with a lgear shaped planingv i cutter, a work 'supporu means orproducing relative cutting movecutter relatively to the work ments between I'the cutter andwork, meansy for rotatingthe cutter and work, mechanism for effecting a graduatedand predetermined valuation in the relation between the axes of the 'cutterandof thework piece, `and means y .for varying the rate of rotation of thecutter in proportion to .the distance between said axes. i Y 'llt A'machine yforgenerating and cutting teeth in i'rregular'gears, comprising in combination a 'gear-shaped' planing cutter, ay workA lholder adapted,V to. support va gear tween said cutter and workholder to cause' cuts, to vbe ,taken across ,the tooth-bearing j. part of the gear" blank, mechanism for giving generating rotatory4 movements to 'the cutter and'work holderin unison, and means for 'gradually increasingand reducing the distance between-the axes" of the cutter and y work holder by distances cumulatively equal tothe dil'eren'cesfin distances of `successi-ve tooth locations yin an irregulargear blanky from the aXis ofthe blank,

spaced teeth-v in a gear at points unequally distant from the center 'of the gear, comprising a cutter having equally lspaced, tooth-like vperiphera'l l projections,v a "work holder adapted zto secure a gear'blank in position to be-operated' on by saidcutter, means, yfor reciprocating said cutterf--Qacross the tooth bearing'portionr of the gear blank, means for" rotating the cutter and work holder simultaneously at' a relatively'slow speed in proportionvtofthe cutting speed of the cutter, and means for' mov ing the cutter V progressively toward and vawayfrom the axis of' vtlie',-g'ear -blank in the progress of cutting the teethonasingleblanlnA blank, means yfor''producing movements bel5. A machine`r `for producing equally 516. A' machine 'for producinglequally y sp'aced'teethinafgear at points unequally distant'from theycent'erof the gear, comprisinga cutter having equally spaced toothlike peripheral"projections, a. work holder adaptedto secure agear blank in positionto be operated on by. sa'id cutter, means lfor rei ciprocating said cutter across'the tooth bearing portionof the/gear blank, means for rotatingl the cutter and work holder simultane` ously at a relatively -slows eed in ypropor tion to the cutting speed `o the cutter, and Ymeans for gradually shifting the cutter toward' andaway from the .aXis ofthe work holderbyamountsequal tothe differences y in the distancesof adjacent teeth of the gear -f from the center of the `gear ed to rotate about its center, aworm wheel y connected to the spindle ofisaid cutter, a.

worin meshing with said wheel, a shaft lfor rotatingsaid worm in respect to which the lwormis freely vmovable endwise, lan end thrust bearing for the worm, and means for shifting saidI end thrust bearing, whereby the ivorm may be moved endwise to impart a `greater or less 'movement tothe worm` wheel than that proportional'to lthe rota.-l A 4tion of 'the worm.

2S. In a machine of the character de*V scribed, including a gear shaped planing cutter adapted to rotate about its axis, a

work holder adaptedalso to rotate about `its axis, *and mechanism for rotating said cutter and workholder in unison, a worm and wheel gear constitutingpart ofsuch "mechanism and a shaft with which such worm is non-rotatably engaged and is movable endwise, an end thrust abutment for said worm, and means for shifting the `posi-y tion of said abutment by predetermined amounts.

" 29. In a gear cutting machine adapted to cutrirregular gears, in combination with `a `gear shaped planing cutter, an automatic mechanism for shifting said cutter bodily anda means for rotating said cutter with a graduated increase and decrease in its rate y of rotation.

y 4nation with a gear shaped planing cutter, Y i i oi work holder,I means for rotating said 30. In a gear cutting machine theeombicutter and work holderin unison, means for changing the distance between the axes of the cutter and work holder, and means for s i ,l n a v u causing a variation inthe rate of rotation 7ot' the cutter.

3l. In a gear cutting machinefincluding a rotatably mounted gear shaped planing cutter, a work support, mechanism for pronducing Such relative movements between the i y cutter and support as to causethe cutter to f f by said support and" to cut grooves therein,

cross the tooth bearingr part'oi a blank held means for simultaneously rotating the cutter and' blank to generate the tooth curves 'in the teeth being cut and at the same time to change the distance between the axes of lthe cutter andwork support to cause the teeth tov be cut in an irregular line, and means for effecting a change in the rate of rotation of the cutter proportional to the change in the difference between such axes. l 32. In a' machine of the character described.` a cutter carriage, a. cutter spindle rotatabl Wheel lconnected 'to -said spindle, a worm meshing with said wheel, a shaft splinedv to said worm on which the latter is movable endwise, a movable end thrust bearingvfor said worm, an abutment forsuch bearing, a cam arranged to take the thrust of said abutment, and gearing driven by said Worm wheel for rotating said cam.

-y mounted in said carriage, a worm 33. Ina`machine of the character de'- scribed, a cutter carriage, a cutter spindle rotatably mounted insaid carriage, a worin Wheel connected to said spindle, a Worin meshing with said wheel, a .shaft splined to said worm onjwliich the latter is movable endwise, a movable end thrust bearing for said worm, an abutment4 for such bearing, aca-ni arranged to take the thrust of said abutment, and gearing drivenv by said worm wheel for rotating said cam.' 34. In a gear cutting machine, a cutter carriage mounted movably, a cutter spindle mounted transversely to the direction of inoreinent of said carriage and rotatably mounted in the carriage, a drive shaft, a cam', speed reducing gearv byfvvhich said drive shaft rotates said cam, and connec tions from the cam to said carriage and arranged to shift said carriage. 'A In testimony whereof I have affixed my signature, in presence of two Witnesses.

E. IV. MiLLEu, i R. M. FnLLows. 

